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Transmission Control Protocol/Internet Protocol (TCP/IP) is an industry standard suite of protocols that computers use to find, access, and
communicate with each other over a transmission medium.A protocol is a set of standards and rules that need to be followed.In t he case of
networking computers, a protocol is the set of standards and rules that a machine's hardware and software must follow in order to be recognized
and understood by other computers.The protocol suite is implemented via a software package most commonly known as the TCP/IP st ack.There
are four general layers of the TCP/IP stack:
z Application layer z Internet layer z Transport layer z Physical or Network Interface layer
The Open Systems Interconnected reference model (OSI/RM) is the standard that all other protocols follow.The OSI/RM provides a framework that
connects heterogeneous systems using a common protocol.It also gives developers universal concepts so they can develop and perf ect protocols.
Each layer of the TCP/IP reference model corresponds to a part of the OSI model.
The TCP/IP reference model and OSI reference model
IPv4 vs. IPv6: Much of the information within this tool is intended for use with IP version 4 (IPv4), the current IP standard.
IP version 6 (IPv6) is on the horizon, however, and you should understand the differences between it and IPv4. To help you
do so, we've included a section comparing IPv6 and IPv4 on page 4.
Contains network applications
and services that the user interfaces with in order to
use network communication.Contains utilities for things
like file and print services and name resolution (for
example, NetBIOS, an application programming inter-
face [API] that supports a desktop operating environ-
ment).Contains utilities that work with TCP/IP to pro-
vide connectivity, file transfer capabilities, utilities for
remote administration, and Internet utilities (for exam-
ple Ping, TRACERT, FTP, and Telnet).
Contains the Transmission
Control Protocol (TCP) and the User Datagram
Protocol (UDP).Used for network connectivity by
applications.Ensures that data is received by the right
machine and that the right application is running on
that machine.Ensures the integrity and completeness
of transmitted data via error checking, flow control,
Contains Internet Protocol (IP),
Address Resolution Protocol (ARP), Internet Control
Message Protocol (ICMP), Reverse Address
Resolution Protocol (RARP), and Internet Group
Management Protocol (IGMP).IP addressing and
address resolution occur within the Internet layer.ARP
resolves logical IP addresses into physical equivalent
addresses.ICMP is mostly used by routers to send
information back to a source computer about a trans-
mission that computer is trying to make.When you
use the Ping utility, the information you receive was
gathered using ICMP.
Network Interface layer:
Contains a collection
of services and specifications that provide and man-
age access to the network hardware.Its responsibili-
Interfacing with the computer's network hardware.
Checking for errors in incoming packets of data.
Tagging outgoing packets with error-checking
Acknowledging the receipt of a packet.
Resending that packet if no acknowledgment is
returned by the recipient.
protocol that establishes a con-
nection with another machine
and maintains that connection for
the duration of data transmission.
More reliable and more widely
used but slower than UDP
Connectionless protocol that
does not establish a persistent
connection with the target
machine.Faster but less
reliable than TCP.
The layers of the OSI Model and how they map to different areas of Microsofts TCP/IP, and the four layers of the
TCP/IP Reference Model and how they map to Microsofts TCP/IP